Definition of Black henna

Black henna: A tattoo ink and paste consisting of henna with other ingredients added, sometimes including para-phenylenediamine (PPD). Allergic reactions to PPD include a contact dermatitis, itching, blisters, open sores, scarring of the skin . Allergic reactions to PPD may also lead to sensitivity to other products such as hair dye, sun block and some types of black clothing. Also called blue henna.